Polishing brush



FIG. 1 is a front elevational view of a polishing brush showing our new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof, a right side view thereof being a mirror image of the left elevational side view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a front right top perspective view thereof; and,

FIG. 7 is a front left bottom perspective view thereof.

The broken lines in the drawings and the areas within broken lines illustrate portions of the polishing brush that form no part of the claimed design. 

CLAIM The ornamental design for a polishing brush, as shown and described. 